Web accessibility refers to computerized tools used by website designers and developers in order to enable interaction with websites for visually impaired users, such as users with reading difficulties or blind users. For example, designers may include text and images that are large in size, or that may be enlarged, in order to provide visually impaired users with the ability to read and understand the content of the page. Another visual tool for enhancing the accessibility of a website is underlining and coloring the links, such that color blind users may more easily detect the links.
In addition to the visual design of a webpage, website designers may also provide infrastructure for usage of other computerized accessibility tools. Screen reader software is one example of a computerized accessibility tool, often used by visually impaired users, that converts digital text into synthesised speech. Screen reader software allow users to listen to content in a website, rather than view the displayed content visually. The screen reader reads out text which is associated with elements displayed in the webpage. The text is often semantically meaningful names of the elements, thus allowing users to navigate the website while listening to the text being read out by the screen reader. A text can be embedded or associated with any element being displayed on the webpage, such as HTML tags, links, icons, menus, dialogue boxes, menus, files and folders.
If a website is properly designed from the accessibility standpoint, i.e. elements of the website have corresponding screen reader functionality and are associated with meaningful readable text, users with disabilities, such as users that are using screen readers, may operate the screen reader function at the user's end, when browsing the website, without requiring authorization or providing any notification to the website operator. Thus, the website operator has no knowledge of whether the screen reader has been operated by a user of the website or not. Moreover, the website operator is unable to obtain information on screen reader usage. The reason is that it may be technically difficult to detect screen readers in the same ways as detecting browser version or screen resolution that are being used by a user's device such as a computer or mobile. While information on browser version or screen resolution can be obtained by a server (in this case, also the website operator) upon receipt of “User-Agent” string, which is sent from the client and includes information that the client sends to the server, screen reader is a third party software application that “lives” on top of the browser and operates directly with the operation system. Therefore, information on usage of a screen reader cannot be obtained by the website operator.
Problems of detecting screen reader users have been recognized in the conventional art and some techniques have been developed to provide solutions. For example, several Windows screen readers make use of the Microsoft Active Accessibility (MSAA) layer, which is an API that enables access technologies to interact with standard and custom UI objects. Applications (such as the Flash Technique) that are intended to detect the usage of screen readers, rely on information that is provided by the MSAA layer to determine usage of screen readers. However, apart from the fact that these applications are limited to usage of specific software/modules (such as Flash or the MSAA layer) or that are Windows based-solutions only, these applications cannot distinguish between usage of screen readers and other accessibility tools, such as a screen magnifier, or a speech recognition application.
Obtaining information on the volume of visually impaired users using a website may motivate website operators to design the website in a more accessible manner. Such information may rely on the amount of usage of screen reader software by users. Accordingly, there is a need for new methods and systems that can facilitate detection of screen reader usage.